如何在android中使用dagger创建一个对象的多个实例

Question

我使用dagger为应用程序创建实例

但由于一些要求，我需要同一对象的多个实例

有人能提出这样做的好方法吗？

Answer 1

您可以使用@Named annotation来实现这种行为，

示例：

步骤1：用带有唯一密钥的@Named注释声明您的方法

@Provides
@Singleton
@Named("cached")
fun someInstance() = return someInstance()

第2步：使用具有声明密钥的实例

@Inject @Named("cached")
val instance: someInstance

Answer 2

您可以使用@Named("创建多个实例。在这里，我创建了两个具有不同@Named("(的拦截器实例

Java:

@InstallIn(SingletonComponent.class)
@Module
class NetworkModule {
@Provides
@Singleton
@Named("headerInterceptor")
private Interceptor provideInterceptor(UserManager userManager) {
return new Interceptor() {
@NonNull
@Override
public Response intercept(@NonNull Chain chain) throws IOException {
return chain.proceed(chain.request());
}
};
}
@Provides
@Singleton
@Named("loggingInterceptor")
private Interceptor provideLoggingInterceptor() {
return new LoggingInterceptor.Builder()
.loggable(BuildConfig.DEBUG)
.setLevel(Level.BODY)
.log(Platform.INFO)
.request("Request")
.response("Response")
.build();
}
@Provides
@Singleton
private OkHttpClient provideOkHttpClient(
Cache cache,
@Named("headerInterceptor") Interceptor interceptor,
@Named("loggingInterceptor") Interceptor loggingInterceptor
) {
return new OkHttpClient.Builder()
.cache(cache)
.connectTimeout(60, TimeUnit.SECONDS)
.readTimeout(60, TimeUnit.SECONDS)
.writeTimeout(60, TimeUnit.SECONDS)
.addInterceptor(interceptor)
.addInterceptor(loggingInterceptor)
.build();
}
}

Kotlin

@InstallIn(SingletonComponent::class)
@Module
class NetworkModule {
@Provides
@Singleton
@Named("headerInterceptor")
fun provideInterceptor(userManager: UserManager): Interceptor {
return Interceptor { chain ->
chain.proceed(chain.request())
}
}
@Provides
@Singleton
@Named("loggingInterceptor")
fun provideLoggingInterceptor(): Interceptor {
return LoggingInterceptor.Builder()
.loggable(BuildConfig.DEBUG)
.setLevel(Level.BODY)
.log(Platform.INFO)
.request("Request")
.response("Response")
.build()
}
@Provides
@Singleton
fun provideOkHttpClient(
cache: Cache,
@Named("headerInterceptor") interceptor: Interceptor,
@Named("loggingInterceptor") loggingInterceptor: Interceptor
): OkHttpClient {
return OkHttpClient.Builder()
.cache(cache)
.connectTimeout(60, TimeUnit.SECONDS)
.readTimeout(60, TimeUnit.SECONDS)
.writeTimeout(60, TimeUnit.SECONDS)
.addInterceptor(interceptor)
.addInterceptor(loggingInterceptor)
.build()
}
}